From a67403af0418e43ca1cdc3b6f2d4507b9174a9aa Mon Sep 17 00:00:00 2001
From: Jan Svabenik <jan@svabi.ch>
Date: Thu, 2 Apr 2026 22:45:09 +0200
Subject: [PATCH] feat: normalize RDS PS and radiotext fields

---
 internal/rds/encoder.go      |  4 +++-
 internal/rds/encoder_test.go | 16 ++++++++++++++++
 internal/rds/normalize.go    | 21 +++++++++++++++++++++
 3 files changed, 40 insertions(+), 1 deletion(-)
 create mode 100644 internal/rds/normalize.go

diff --git a/internal/rds/encoder.go b/internal/rds/encoder.go
index 1a62279..854a746 100644
--- a/internal/rds/encoder.go
+++ b/internal/rds/encoder.go
@@ -1,7 +1,7 @@
 package rds
 
 import (
-	"math"
+    "math"
 )
 
 const (
@@ -29,6 +29,8 @@ func NewEncoder(cfg RDSConfig) (*Encoder, error) {
 	if cfg.SampleRate <= 0 {
 		cfg.SampleRate = 48000
 	}
+    cfg.PS = normalizePS(cfg.PS)
+    cfg.RT = normalizeRT(cfg.RT)
 
 	bits := buildBits(cfg)
 	if len(bits) == 0 {
diff --git a/internal/rds/encoder_test.go b/internal/rds/encoder_test.go
index 964acee..0b5c8b2 100644
--- a/internal/rds/encoder_test.go
+++ b/internal/rds/encoder_test.go
@@ -2,6 +2,7 @@ package rds
 
 import (
 	"math"
+	"strings"
 	"testing"
 )
 
@@ -49,3 +50,18 @@ func TestEncoderReset(t *testing.T) {
 		t.Fatalf("expected reset to replay initial sample: %v vs %v", sampleA, sampleB)
 	}
 }
+
+func TestNormalizePS(t *testing.T) {
+    got := normalizePS("radiox")
+    if got != "RADIOX  " {
+        t.Fatalf("unexpected PS: %q", got)
+    }
+}
+
+func TestNormalizeRT(t *testing.T) {
+    long := strings.Repeat("a", 80)
+    got := normalizeRT(long)
+    if len(got) != 64 {
+        t.Fatalf("unexpected RT length: %d", len(got))
+    }
+}
diff --git a/internal/rds/normalize.go b/internal/rds/normalize.go
new file mode 100644
index 0000000..1dfeb7d
--- /dev/null
+++ b/internal/rds/normalize.go
@@ -0,0 +1,21 @@
+package rds
+
+import "strings"
+
+func normalizePS(ps string) string {
+    ps = strings.ToUpper(ps)
+    if len(ps) > 8 {
+        ps = ps[:8]
+    }
+    if len(ps) < 8 {
+        ps = ps + strings.Repeat(" ", 8-len(ps))
+    }
+    return ps
+}
+
+func normalizeRT(rt string) string {
+    if len(rt) > 64 {
+        rt = rt[:64]
+    }
+    return rt
+}